In commercial building applications (for example, a store front) mechanical lock cylinders, such as mechanical, tumbler-based lock cylinders, are often used to secure the front door. In many such applications, local ordinances require a “backup” or “duplicate” of the mechanical key that operates the door lock to be stored in a protected “box” or “tube” that is accessible, e.g., by emergency personnel, from the outside of the building. Knox Company is a well-known provider of these types of boxes, known as the “Knox Box.” The backup mechanical key is used by agencies, such as fire and rescue departments, to gain access to the building in the event of an emergency during off hours or whenever the door is locked. The box storing the backup building key is secured by a different lock that only the emergency agencies have a key to access.
The use of electronic cylinders has become more prevalent in commercial, industrial, and other similar facilities. A typical electronic cylinder comprises an electro-mechanical actuator mounted within the door and configured to selectively lock or unlock a door lock mechanism, such as traditional rim lock or mortise lock hardware application, when activated by a properly programmed electronic key. Such electronic cylinders provide certain advantages that are not available with traditional mechanical cylinders. For example, electronic cylinders can be electronically re-keyed and can be programmed to provide time-based access control to the door to thereby allow access only at certain, predetermined times of day. Electronic cylinders also provide audit information as each electronic key can be programmed to emit a unique signature that is captured by the lock control system when the key is used to access the facility.
When an electronic retrofit cylinder is utilized on a door to control access to a building subject to such ordinances, the mechanical cylinder is replaced with the electronic cylinder, and the mechanical key stored in the protected box is no longer usable to gain access to the door. In this context, the term “retrofit cylinder” means a cylinder having the same physical and operational configuration as an existing cylinder so that it can replace an existing cylinder by fitting into the compartment formed in the door for holding the cylinder lock and it will interoperate with the existing door lock/latch mechanism in the same manner as the replaced cylinder.
In order to meet the requirements of local ordinances for providing access to the front door in the event of an emergency, an electronic key would be need to be stored in the emergency access key box. This is problematic in that an electronic key is typically battery-powered (either replaceable or rechargeable batteries) and it would be necessary to recharge or replace batteries in the electronic key frequently to ensure the key would be operational when needed by the emergency personnel. Additionally, batteries may degrade badly or cease to work in some environments due to the severe temperatures (hot and cold) encountered inside the storage box mounted on the outside of the building.
To avoid these shortcomings, for an electronic cylinder to be practicably usable in a facility subject to such emergency access ordinances, the electronic cylinder should also be operable by a mechanical key that can be stored externally of the facility in an emergency access key box. Unfortunately, a retrofit cylinder that is configured to replace an existing mechanical lock cylinder without requiring a substantial reconfiguration of the door and door latch, and which is operable by a mechanical override key as well as the primary electronic key(s) is not available. Accordingly, there is a need for electronic retrofit cylinder with mechanical override.
In other applications, there are advantages to a retrofit cylinder lock having two electronic cylinders, which are not realized in the application described above with respect to the “Knox Box,” where a backup or secondary key is required to be stored in the box for emergency personnel to gain access. In such applications, a retrofit cylinder lock having a second, electronic cylinder option—as opposed to a second, mechanical option—has benefits where the lock cylinder may be utilized. The need to provide independent access to a “shared” asset between two independent management systems is one benefit. Because each electronic cylinder is electronically “unique”, each cylinder can be assigned to a different management system. Keys programmed from one system can only access “their” electronic cylinder. The other system can only program keys to access “their” cylinder. Providing access is not dependent on a single party (or system) to provide programming of all keys for access.
An exemplary application is a lock installed on the door of an ATM back room. The ATM service provider can program their key to gain access as needed to gain access to service or repair the ATM. The armored car company needs access to replenish cash in the ATM. They have the ability to program a key from their system to open the door using their cylinder. Neither of these users is dependent on the other for access. In this example, for security purposes, it is better if the service provider does not know when the armored car will be there. The additional benefit over one mechanical and one electronic cylinder is that with two electronic cylinders there is a recorded audit record stored in each cylinder and each key for all accesses. In an application in which one of the cylinders is a mechanical cylinder, there is no audit of the mechanical cylinder being used to access or open the door.
Accordingly, there is also a need for an electronic retrofit cylinder lock that includes two electronic cylinder plugs.